High voltage fuse



Aug. 18, 1931. R. REICHMANN ET AL 1,819,198

HIGH VOLTAGE FUSE Filed June 27, 1927 WITNESSES: INVENTOR Reinhold Relchmann Patented Aug. 18, 1931 BEINHOLD REIGHMANN AND KARL ZIMMERMANN, OF BERLIN, GERMANY, ASSIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORIORATION OF PENNSYLVANIA HIGH VOLTAGE FUSE Application filed June 27, 1927, Serial No.

Our invention relates to circuit interrupters and more particularly to fuses for interrupting high-voltage circuits.

One object of our invention is to provide a fuse for a high-voltage circuit that shall have means for deionizing the arc path after the rupturing of the fuse element to prevent the are formed thereby from restriking after the current has assed through zero value.

Another object of our invention is to provide a fuse structure that shall enclose means for deionizing the arc path by chemical change.

A still further object of our invention is to provide a fuse for a high-voltage circuit that shall be capable of extinguishing an are by means other than a cooling fluid, thereby providing a structure that may be employed effectively on indoor circuits.

A still further object of our invention is to provide a fuse that shall have means whereby the gases and vapors accompanying an are are removed from the surrounding tubular container so that the arc is deprived of the gases and vapors necessary to its existence.

Heretofore successful fuses for high-voltage circuits have employed a quenching fluid into which one terminal moved and drew the are into a liquid, thereby extinguishing it.

This structure is limited to outdoor application, as the liquid is usually ejected from the container upon the rupturing of the fuse element and this causes damage to adjoining apparatus. For example, if oil employed as a cooling medium,

fire is likely to result. It is an object of our invention to construct a fuse that may be employed efliciently indoors as well as outdoors, and this we accomplish by employing means'other than a liquid for extinguishing the are.

These and other objects of ourinvention, which will be made apparent in the accompanying specification, will best be understood by referring to the drawings, in which:

Figure 1 is a view, partly in section and artly in elevation, showing a particular em- Bodiment of our invention.

Fig. 2 is a v1ew,.1n section, showing another form that our invention may assume.

201,822, and in Germany June 26, 1926.

According to the present invention, electric discharges, especially those involving relatively large amounts of energy, are sup pressed or prevented entirely, by the introduction into the path of the discharge, of materials which will withdraw so many electrons or ions from the discharge that the remainder will not be sufficient to maintain an arc It is especially desirable to use materials or a mixture thereof which will simultaneously absorb electrons and ions and, particularly, metal ions.

As a specific example of this, the product on of an arc caused by the destructlon of a sllver fuse may be prevented by the use of halogens or some combination thereof, as the electron or ion-absorbing materials. Not all the halogens are equally efiective, however, and it is advisable to employ halogen compounds which are so constituted that their products of decomposition will not maintain the arc. Thus, in suppressing the arcs produc'ed by silver fuses, it has been found desirable to use halogen-oxygen compounds, such as iodic anhydride I 0 In the course of operation of the device, the wire will fuse, and the high temperature will decompose the iodic acid into iodine atoms and oxygen, and the arc, which would normally have been formed after the vaporization of the Wire, will not be formed at all, as the silver ions necessary for the arc will combine with free iodine atoms and form electrically neutral silver iodide, and all the electrons produced will be made unsuitable for maintaining current flow by combining with the free iodine atoms, to form negative iodine ions which leave but a low mobility.

Instead of, halogen oxygen compounds, we may employ halogen compounds of silicon and get substantially the same results. Mixing the electron or ion-absorbing material with filling materials which are disassociated with difliculty and which, possess low conductivity at high temperatures, will help in suppressing the arcing. In the latter case, there is added to the action of the electron or ion-absorbing material, the deionizing action of the finely divided filling material,

which has a strong tendency arc and also the vapors.

In the drawings, a silver wire 1 is located in a tube 2 consisting of insulating material, the ends thereof being connected to cap members 3, 4. The tube 2 is contained within a tubular casing 5, also of insulating material. Leads 6 and 7 connect the ends of the fusible wire 1 to cap members 8 and 9. The interior of the tube 2 is filled with a material 11, which, when decomposed, develops materials tending to remove ions, such as iodic anhydride L0, or iodic anhydride and a filler. The filler is preferably such that it will not disassociate at higher temperatures and become conducting. Boron nitride is such a material.

In order to prevent a condition wherein a gradual decomposition of the electron or ion-absorbing material is produced by an over-load too slight to rupture thefusible conductor, we may provide, at one portion of the fusible wire, a material which decomposes readily, for example, nitrocellulose, as indicated at 12. This may also constitute an expulsion means which will remove all of the products of decomposition from the tube, and the easily decomposable material 12 should, therefore, be such that it will not aid the arc. For this reason, no saltpetre to quench the should be used in its composition. The design of such a structure is shown in Fig. 2, wherein the end caps 3 and 4 are open at their ends, and the tube 2 is supported by washers 13 and 14 within the casing 5. The leads 6 and 7 are no longer the support of the tube 2, as in Fig. 1, but are brought out through the side of the casing 5, thereby leaving the ends of the tube 2 open.

When an arc is formed by the fusion of the wire 1, the easily ignitable material 12 produces a force that expels the gases and vapors along with the remaining deionizing material 11 out through the end caps 3 and 4, thereby aiding the deionizing material 11 in extinguishing the arc.

It will thus be seen that we have invented a fuse for a high-voltage electric circuit that will be ruptured on overloads by the employment of the easily ignitable material, one that will extinguish the are within a half cycle after rupture by the deionizing substance employed therein, and which utilizes an easily ignitable material as an auxiliary to produce a pressure, whereby the vapors and gases, alongwith the remaining deionizing material, are expelled from the structure.

It will be recognized that the employment of materials which reduce ionization in the are path through the agency of chemical action and the use of a decomposable sub stance to rend the fuse on ru turing are adjunctive devices and that eit er may be employed alone when so desired.

Various modifications may be made with.- out departing from the spirit and the scope of our invention, and we desire, therefore. that only such limitations shall be placed thereon as are imposed by the prior art and set forth in the appended claims.

We claim as our invention:

1. A fuse structure including a body portion having end closures, a fuse element contained therein and a substance thereabout that is readily decomposed by the heat of fusion producing stable atoms that have an afiinity for the liberated metal ions and a non-conducting filler about the said substance enclosed in the body portion.

2. A fuse structure comprising a body portion having end closures, a fuse element of silver contained therein and iodine anhydride 0 K )laced around the fuse element.

3. fuse structure comprising a body portion having end closures, a fuse element of silver contained therein and iodine anhydride (I 0 mixed with a filler of boron nitride in the vicinity of the fuse element.

1. A fuse structure comprising a body portion having end closures, a fuse element contained therein and a halogen-oxygen compound about the fuse element.

5. A fuse structure comprising a body portion having end closures, a fuse element contained therein and a halogen-oxygen compound and a filler of boron nitride within the body portion.

6. A fuse structure including a body portion of insulating material having electrical conducting end terminals, a fuse element supported within the body portion by the end terminals, and an ion absorbing material that is disassociated by the heat of fusion forming stable atoms mixed with an inert low conductive substance that surrounds the fuse element and fills the body portion.

7. The combination with a fuse structure including a plurality of casings, one supported within the other, of closure members for the ends of each casing, a fuse element within the inner casing electrically connected to the closure member, and a halogen compound mixed with boron nitride for deionizing the arc path.

8. The combination with a fuse structure including a plurality of casings, one sup ported within the other, of closure members for the ends of each casing, a fuse element within the inner casing electrically connected to the closure member, a deionizing means about the fuse element. and an easily ignitable means about a portion of the fuse element to assist rupture when a condition of overload is present in the circuit.

9. The combination, in a fuse structure including an outer and an inner casing havin terminal members on the ends thereof, the terminal members on the inner casing having an aperture, of a fuse element disposed in the inner casing electrically connected to the end terminals, a deionizing substance in the inner casing about the fuse element, and an expulsion means in a portion of the inner casing to expel the vapors and gases throu h the aperture in the inner casin terminals.

10. A fuse structure including a body portion having an open end, a fuse element contained therein and a substance thereabout that is readily decomposed by the heat of fusion, producing stable atoms that have an aflinity for the liberated metal ions and a non-conducting filler about the said substance enclosed in the body portion.

11. A fuse structure comprising a body portion having an open end, a fuse element of silver contained therein and iodine anhydride (I 0 placed around the fuse element.

12. A fuse structure comprising a body portion having an open end, a fuse element contained therein and a halogen-oxygen compound about the fuse element.

13. A fuse structure comprising a body portion having an open end, a fuse element contained therein and a halogen-oxygen compound and a filler of boron nitride within the body portion.

14;. A fuse structure including a body 7 portion of insulating material having electrical conducting end terminals one of which is open, a fuse element supported within the body portion by the end terminals, and an ion absorbing material that is disassociated by the heat of fusion forming stable atoms mixed with an inert low conductive substance that surrounds the fuse element and fills the body portion.

In testimony whereof, we have hereunto subscribed our names.

REINHOLD REICHMANN. KARL ZIMMERMANN. 

